test: handle relative https redirect

[richardlau]

Fix internet/test-inspector-help-page to handle the relative redirect of https://nodejs.org/en/docs/inspector to /en/docs/guides/debugging-getting-started. Previously this URL redirected to an absolute URL.

---

The internet/test-inspector-help-page test has been failing for about a week:

• On node-daily-master in Jenkins since 6 December 2023, e.g.
  • https://ci.nodejs.org/view/Node.js%20Daily/job/node-daily-master/3253/
    • https://ci.nodejs.org/job/node-test-commit-custom-suites-freestyle/33912/testReport/junit/(root)/test/internet_test_inspector_help_page/
• On GitHub Actions, e.g.
  • https://github.com/nodejs/node/actions/runs/7108379296/job/19351546344

=== release test-inspector-help-page ===
Path: internet/test-inspector-help-page
node:internal/url:787
    this.#updateContext(bindingUrl.parse(input, base));
                                   ^

TypeError: Invalid URL
    at new URL (node:internal/url:787:36)
    at request (node:https:366:32)
    at Object.get (node:https:414:15)
    at check (/home/runner/work/node/node/test/internet/test-inspector-help-page.js:17:9)
    at ClientRequest.<anonymous> (/home/runner/work/node/node/test/internet/test-inspector-help-page.js:21:14)
    at ClientRequest.<anonymous> (/home/runner/work/node/node/test/common/index.js:476:15)
    at Object.onceWrapper (node:events:634:26)
    at ClientRequest.emit (node:events:519:28)
    at HTTPParser.parserOnIncomingClient [as onIncoming] (node:_http_client:6[93](https://github.com/nodejs/node/actions/runs/7108379296/job/19351546344#step:6:94):27)
    at HTTPParser.parserOnHeadersComplete (node:_http_common:119:17) {
  code: 'ERR_INVALID_URL',
  input: '/en/docs/guides/debugging-getting-started'
}

Node.js v22.0.0-pre
Command: out/Release/node /home/runner/work/node/node/test/internet/test-inspector-help-page.js

The test attempts to connect to https://nodejs.org/en/docs/inspector (output from node --inspect -e ""), and then to res.headers.location which comes back as /en/docs/guides/debugging-getting-started.

Presumably something changed around then on the website so that the redirect is now to a relative URL rather than an absolute one. The test itself hasn't changed in over a year.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/56232/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/56241/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/56244/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/56250/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/56253/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/56254/

[nodejs-github-bot]

Landed in 99f6084